Cockroaches, Beetles, and other Nuisance orders Announcements Presentation Schedule Reading: Chap 7.

Cockroaches, Beetles, and other Nuisance orders

AnnouncementsPresentation ScheduleReading: Chap 7

A Key Concept in DV Management is Risk

• Most DV Management is Govt. Funded• They fund efforts in response to perceived risk• Risk = Cost of a Bad Outcome

TIMESProbability of that Outcome

Occurring

The main problem is there are multiple risks

• Multiple “Bad Outcomes” including– Economic– Environmental– Social– Political

• Each outcome has it’s own cost and probability

• Major Complication: Disease risk is inversely correlated with vector control.

Nuisance Species – Species which lack a direct or vectored

medical/veterinary impact

• Temporary (e.g. overwintering) invaders. E.g. crickets, lady beetles.

• Permanent, non-medical/veterinary inhabitants. E.g. booklice, fungus gnats, etc.

• Permanent inhabitants with medical/veterinary significance– Indirect issues – the subject of this lecture

Nuisance species generally cause these types of problems

• Some food-borne disease• Other surface contamination disease• Intermediate/secondary hosts• Allergies & Asthmatic Reactions• Psychiatric/psychological disorders• Social stigma• Degrades quality of life (they’re disgusting)

Cockroaches in General

• Cockroaches the most common insect pests infesting homes, food service establishments and other structures in in the US. • There are over 4,000 species of cockroaches in the world and numerous species can become pests in the US. • Generally, the further south one goes, the more pest species there are with which to deal.

Cockroach Infestation

Cockroach Infestation

Cockroach Infestation

Cockroach Infestation

Cockroach Infestation

Cockroach Infestation

Main Problem of Cockroaches – Allergy X Asthma Interaction

• Allergy -- a hypersensitive state acquired through exposure to a particular allergen, reexposure bringing to light an altered capacity to react. Most common type with cockroaches is “Atopic”

• Asthma - a chronic (long-lasting) inflammatory disease of the airways. 90% of cases are “Extrinsic”

• Interaction between the two is usually expressed as Bronchial Hyperresponsivness (BHR). BHR is an exaggerated bronchial constriction in response to specific or nonspecific provocation.

Inflammation of Bronchial Wall

Constriction of Bronchial Muscles

Cockroach-mediated BHR (CM-BHR)

• A combination of social, genetic, and cockroach-specific factors.

• Increasing in North American & European inner cities at about 75%/10 years - the problem is growing.

• Incidence increases as one moves up the NIH Asthma severity scale:– Mild Intermittent Asthma: Pulmonary function >= 80% of normal ;

Episodes infrequent. CM-BHR Incidence < 20%– Mild Persistent Asthma: Pulmonary function >= 80% of normal;

Episodes > 2/week but < 1/day; Normal activity affected. CM-BHR < 20 – 40%

– Moderate Persistent Asthma: Pulmonary function >= 60% but < 80% of normal. Episodes frequent. Daily use of inhaler. Activity significantly affected. CM-BHR Incidence 40 -80%

– Severe Persistent Asthma: Pulmonary function <= 60%. Episodes continuous & limited physical activity. CM-BHR > 80%

CM-BHR Epidemiology – Likelihood that a child will have CM-BHR in S. New England, 2006

Cockroaches in Kentucky• In Kentucky, we are primarily concerned with

four species: – German cockroach, Blatella germanica L., – brownbanded cockroach, Supella longipalpa F., – oriental cockroach, Blatella orientalis L., – American cockroach, Periplaneta americana L.

• Of these, the one that has is most troublesome is the German cockroach, which prefers indoor locations.

• Oriental and American cockroaches occasionally pose problems in moist, humid areas.

Kentucky Cockroaches -- Adults

Basic Life Cycle

• Incomplete Metamorphosis• Eggs deposited in “packs” called oothecae• 3 – 5 nymphal instars• Total lifespan in a dwelling – 8 – 12 weeks• Most temperate pest species lack overwintering stage.

Life Stages of the German Cockroach

Kentucky Cockroaches – Oothecae

Cockroach Control

• See your text on pp. 55• Gel Baits are the most

effective controls at present

• Many are general use

Baits are typically used with traps

0

100

200

300

400

500Co

ckro

ache

s/tr

ap

0 1 3 6 9 12

Months Post Treatment

ControlBait

A single bait treatment can be highly effective in reducing cockroachesFrom: Sever et al. 2007

More Importantly, Chemical Baits Alone Can Reduce Allergens (ibid)

Biocontrol continues to draw interest – Interesting Aside: The Jewel Wasp

• Stings roach in the brain. Venom paralyzes the part of brain that controls free will. Zombie roach with follow the wasp anywhere.

• National Geographic article, 2007• YouTube Video

Beetles

• Chapter 8 in your text.• Largest order of insects: 350,000 spp or about

40% of all insect spp. This is really the only reason that we mention them in this class.

• Most are either phytophagous or predatory. Minor significance to human and animal health.

Beetles

• Most problems in our area are either as nuisance species (lady beetles) or veterinary problems (ingestion of toxic beetles).

• Intermediate hosts of many veterinary pathogens (see text)

• Some have medically-important benefits– Forensic entomology– Some medicinal products– Some interrupt disease transmission in mammals (e.g.

dung beetles).

Beetle Morphology

• Distinctive wing arrangement

• Holometabolous• Abdomen broadly

joined to the pterothorax

Blister beetles

• Most common toxic beetle in Kentucky

• Striped blister beetle is the most common species

• Often occur in swarms or clusters.

Blister Beetles

• All possess a terpenoid, cantharidin, which causes blisters

• Human LD50 is 0.5 mg/kg, 10 mg could be fatal.

• Cantharidin is carried in the beetle’s blood.

• In all life stages• Available commercially as a

wart treatment.